HTTP/2 Frame Writer Microbenchmark Fix

Motivation:
The Http2FrameWriterBenchmark JMH harness class name was not updated for the JVM arguments. The number of forks is 0 which means the JHM will share a JVM with the benchmarks.  Sharing the JVM may lead to less reliable benchmarking results and as doesn't allow for the command line arguments to be applied for each benchmark.

Modifications:
- Update the JMH version from 0.9 to 1.7.1.  Benchmarks wouldn't run on old version.
- Increase the number of forks from 0 to 1.
- Remove allocation of environment from static and cleanup AfterClass to using the Setup and Teardown methods. The forked JVM would not shut down correctly otherwise (and wait for 30+ seconds before timeing out).

Result:
Benchmarks that run as intended.

microbench/pom.xml

@@ -73,12 +73,12 @@
     <dependency>
       <groupId>org.openjdk.jmh</groupId>
       <artifactId>jmh-core</artifactId>
-      <version>0.9</version>
+      <version>1.7.1</version>
     </dependency>
     <dependency>
       <groupId>org.openjdk.jmh</groupId>
       <artifactId>jmh-generator-annprocess</artifactId>
-      <version>0.9</version>
+      <version>1.7.1</version>
       <scope>provided</scope>
     </dependency>
   </dependencies>

microbench/src/test/java/io/netty/microbench/http2/Http2FrameWriterBenchmark.java

@@ -34,7 +34,6 @@ import io.netty.channel.ChannelPipeline;
 import io.netty.channel.EventLoop;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.ServerChannel;
-import io.netty.channel.epoll.Epoll;
 import io.netty.channel.epoll.EpollEventLoopGroup;
 import io.netty.channel.epoll.EpollServerSocketChannel;
 import io.netty.channel.epoll.EpollSocketChannel;
@@ -66,17 +65,15 @@ import io.netty.util.concurrent.Future;
 
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
-import java.util.HashMap;
-import java.util.Map;
 import java.util.Random;
 
-import org.junit.AfterClass;
 import org.openjdk.jmh.annotations.Benchmark;
 import org.openjdk.jmh.annotations.Level;
 import org.openjdk.jmh.annotations.Param;
 import org.openjdk.jmh.annotations.Scope;
 import org.openjdk.jmh.annotations.Setup;
 import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.TearDown;
 
 @State(Scope.Benchmark)
 public class Http2FrameWriterBenchmark extends AbstractSharedExecutorMicrobenchmark {
@@ -94,37 +91,26 @@ public class Http2FrameWriterBenchmark extends AbstractSharedExecutorMicrobenchm
             new OioEnvironmentParametersBase(PooledByteBufAllocator.DEFAULT);
 
     public static enum EnvironmentType {
-        EMBEDDED_POOLED, EMBEDDED_UNPOOLED,
+        EMBEDDED_POOLED(NIO_POOLED_PARAMS), EMBEDDED_UNPOOLED(NIO_UNPOOLED_PARAMS),
-        NIO_POOLED, NIO_UNPOOLED,
+        NIO_POOLED(NIO_POOLED_PARAMS), NIO_UNPOOLED(NIO_UNPOOLED_PARAMS),
-        EPOLL_POOLED, EPOLL_UNPOOLED,
+        EPOLL_POOLED(EPOLL_POOLED_PARAMS), EPOLL_UNPOOLED(EPOLL_UNPOOLED_PARAMS),
-        OIO_POOLED, OIO_UNPOOLED;
+        OIO_POOLED(OIO_POOLED_PARAMS), OIO_UNPOOLED(OIO_UNPOOLED_PARAMS);
+
+        private final EnvironmentParameters params;
+
+        private EnvironmentType(EnvironmentParameters params) {
+            this.params = params;
+        }
+
+        public EnvironmentParameters params() {
+            return params;
+        }
     }
 
     public static enum DataPayloadType {
         SMALL, MEDIUM, LARGE, JUMBO;
     }
 
-    private static final Map<EnvironmentType, Environment> ENVIRONMENTS = new HashMap<EnvironmentType, Environment>();
-    private static final Map<DataPayloadType, BenchmarkTestPayload> PAYLOADS =
-            new HashMap<DataPayloadType, BenchmarkTestPayload>();
-
-    static {
-        ENVIRONMENTS.put(EnvironmentType.OIO_POOLED, boostrapEnvWithTransport(OIO_POOLED_PARAMS));
-        ENVIRONMENTS.put(EnvironmentType.OIO_UNPOOLED, boostrapEnvWithTransport(OIO_UNPOOLED_PARAMS));
-        ENVIRONMENTS.put(EnvironmentType.NIO_POOLED, boostrapEnvWithTransport(NIO_POOLED_PARAMS));
-        ENVIRONMENTS.put(EnvironmentType.NIO_UNPOOLED, boostrapEnvWithTransport(NIO_UNPOOLED_PARAMS));
-        if (Epoll.isAvailable()) {
-            ENVIRONMENTS.put(EnvironmentType.EPOLL_POOLED, boostrapEnvWithTransport(EPOLL_POOLED_PARAMS));
-            ENVIRONMENTS.put(EnvironmentType.EPOLL_UNPOOLED, boostrapEnvWithTransport(EPOLL_UNPOOLED_PARAMS));
-        }
-        ENVIRONMENTS.put(EnvironmentType.EMBEDDED_POOLED, boostrapEmbeddedEnv(PooledByteBufAllocator.DEFAULT));
-        ENVIRONMENTS.put(EnvironmentType.EMBEDDED_UNPOOLED, boostrapEmbeddedEnv(UnpooledByteBufAllocator.DEFAULT));
-        PAYLOADS.put(DataPayloadType.SMALL, createPayload(DataPayloadType.SMALL));
-        PAYLOADS.put(DataPayloadType.MEDIUM, createPayload(DataPayloadType.MEDIUM));
-        PAYLOADS.put(DataPayloadType.LARGE, createPayload(DataPayloadType.LARGE));
-        PAYLOADS.put(DataPayloadType.JUMBO, createPayload(DataPayloadType.JUMBO));
-    }
-
     @Param
     public EnvironmentType environmentType;
 
@@ -138,28 +124,31 @@ public class Http2FrameWriterBenchmark extends AbstractSharedExecutorMicrobenchm
 
     private BenchmarkTestPayload payload;
 
-    @AfterClass
-    public static void teardown() {
-        for (Environment env : ENVIRONMENTS.values()) {
-            try {
-                env.teardown();
-            } catch (Exception e) {
-                handleUnexpectedException(e);
-            }
-        }
-        for (BenchmarkTestPayload payload : PAYLOADS.values()) {
-            payload.release();
-        }
-    }
-
     @Setup(Level.Trial)
     public void setup() {
-        environment = ENVIRONMENTS.get(environmentType);
+        switch (environmentType) {
+        case EMBEDDED_POOLED:
+        case EMBEDDED_UNPOOLED:
+            environment = boostrapEmbeddedEnv(environmentType);
+            break;
+        default:
+            environment = boostrapEnvWithTransport(environmentType);
+            break;
+        }
         if (environment == null) {
             throw new IllegalStateException("Environment type [" + environmentType + "] is not supported.");
         }
         AbstractSharedExecutorMicrobenchmark.executor(environment.eventLoop());
-        payload = PAYLOADS.get(dataType);
+        payload = createPayload(dataType);
+    }
+
+    @TearDown(Level.Trial)
+    public void teardown() throws Exception {
+        try {
+            environment.teardown();
+        } finally {
+            payload.release();
+        }
     }
 
     @Benchmark
@@ -233,7 +222,8 @@ public class Http2FrameWriterBenchmark extends AbstractSharedExecutorMicrobenchm
         }
     }
 
-    private static Environment boostrapEnvWithTransport(final EnvironmentParameters params) {
+    private static Environment boostrapEnvWithTransport(final EnvironmentType environmentType) {
+        final EnvironmentParameters params = environmentType.params();
         ServerBootstrap sb = new ServerBootstrap();
         Bootstrap cb = new Bootstrap();
         final TrasportEnvironment environment = new TrasportEnvironment(cb, sb);
@@ -282,7 +272,8 @@ public class Http2FrameWriterBenchmark extends AbstractSharedExecutorMicrobenchm
         return environment;
     }
 
-    private static Environment boostrapEmbeddedEnv(final ByteBufAllocator alloc) {
+    private static Environment boostrapEmbeddedEnv(final EnvironmentType environmentType) {
+        final ByteBufAllocator alloc = environmentType.params().clientAllocator();
         final EmbeddedEnvironment env = new EmbeddedEnvironment(new DefaultHttp2FrameWriter());
         final Http2Connection connection = new DefaultHttp2Connection(false);
         Http2ConnectionEncoder encoder = new DefaultHttp2ConnectionEncoder(connection, env.writer());

microbench/src/test/java/io/netty/microbench/util/AbstractMicrobenchmarkBase.java

@@ -42,7 +42,7 @@ public abstract class AbstractMicrobenchmarkBase {
     protected static final int DEFAULT_MEASURE_ITERATIONS = 10;
     protected static final String[] BASE_JVM_ARGS = {
         "-server", "-dsa", "-da", "-ea:io.netty...", "-XX:+AggressiveOpts", "-XX:+UseBiasedLocking",
-        "-XX:+UseFastAccessorMethods", "-XX:+UseStringCache", "-XX:+OptimizeStringConcat",
+        "-XX:+UseFastAccessorMethods", "-XX:+OptimizeStringConcat",
         "-XX:+HeapDumpOnOutOfMemoryError", "-Dio.netty.noResourceLeakDetection"};
 
     static {

microbench/src/test/java/io/netty/microbench/util/AbstractSharedExecutorMicrobenchmark.java

@@ -33,13 +33,13 @@ import org.openjdk.jmh.annotations.Fork;
 @Fork(AbstractSharedExecutorMicrobenchmark.DEFAULT_FORKS)
 public class AbstractSharedExecutorMicrobenchmark extends AbstractMicrobenchmarkBase {
 
-    protected static final int DEFAULT_FORKS = 0; // Forks has to be 0 so tasks are run immediately by JMH
+    protected static final int DEFAULT_FORKS = 1;
     protected static final String[] JVM_ARGS;
 
     static {
         final String[] customArgs = {
         "-Xms2g", "-Xmx2g", "-XX:MaxDirectMemorySize=2g", "-Dharness.executor=CUSTOM",
-        "-Dharness.executor.class=io.netty.microbench.util.AbstractExecutorMicrobenchmark$DelegateHarnessExecutor" };
+    "-Dharness.executor.class=io.netty.microbench.util.AbstractSharedExecutorMicrobenchmark$DelegateHarnessExecutor" };
 
         JVM_ARGS = new String[BASE_JVM_ARGS.length + customArgs.length];
         System.arraycopy(BASE_JVM_ARGS, 0, JVM_ARGS, 0, BASE_JVM_ARGS.length);